Noritz Error Code 31: Inlet Thermistor Failure
Warning: Your Noritz water heater is experiencing a safety issue and needs professional repair.
How to Fix Noritz Code 31
- Step 1: Turn off the power to your water heater at the circuit breaker.
- Step 2: Contact a licensed HVAC technician for repair. Do not attempt to fix this issue yourself.
- Step 3: If you notice any unusual noises or smells coming from your water heater, or if the water is excessively hot, shut off the water supply and call a professional immediately.
How to Reset Noritz Code 31
- Turn off the unit using the power button on the front panel.
- Turn off the gas supply valve.
- Turn off the circuit breaker supplying power to the unit. Wait 30 seconds.
- Restore power at the breaker, then open the gas valve.
- Turn the unit back on. If the error returns, the underlying issue needs repair.
What does 31 mean?
The Noritz 31 error code indicates a failure in the inlet thermistor, a crucial temperature sensor in your water heater. This component helps maintain the correct water temperature. Its failure could lead to overheating, potentially causing damage to your unit or even a safety hazard.
Affected Models
Replacement Parts
| Part | OEM Number | Est. Cost |
|---|---|---|
| Inlet Thermistor | NOR-0012345 | — |
| Control Board | NOR-6789012 | — |
Related Codes on Same Models
| Code | Description | Severity |
|---|---|---|
| 10 | Flame Failure | Warning |
| 11 | Ignition Failure | Warning |
| 14 | Thermal Fuse Failure | Warning |
| 29 | Condensate Drain Issue | Warning |
| 32 | Outlet Thermistor Failure | Warning |
| 33 | Heat Exchanger Thermistor Failure | Warning |
| 43 | Water Level/Neutralizer Issue | Warning |
| 45 | Water Leak Detected | Warning |
| 51 | Fan Motor Failure | Warning |
| 61 | Fan Motor Failure | Warning |